March 17, 2019
Today's focus was to get some tabbing done on a couple areas of the boat that I had intended to do for a couple weeks now - the bulkhead supporting the cockpit well and the chainplate knees. To begin, I solvent-washed the cockpit bulkhead (the focus today was the aft face of the port side of this bulkhead) and the four chainplate knees (two each to port and starboard). I then took measurements of the tabbing material required for the various structural work. I measured both 4" and 6" lengths of the 1708 biaxial tape for the cockpit bulkhead. I then measured various lengths of the same 4" and 6" biaxial material for the chainplate knees. In all, 10.8 feet of 4" tabbing material and 7.6 feet of the 6" tabbing biaxial.
I returned to the shop and prepared the various lengths of material.
I started with the cockpit bulkhead. I wet out the surfaces of the hull and existing bulkhead with straight epoxy resin, and followed that with a pot of thickened epoxy to create a fillet, a radius, between the vertical surface of the bulkhead and the horizontal surface of the hull. This fillet would allow the biaxial tape to lay down without voids forming. With the surfaces on the boat properly prepared, I then wet out the 4" 1708 biaxial tape, carried it to the boat and applied it. I made sure to remove any trapped air bubbles from the applied laminate. I repeated this process for the 6" biaxial tape.
With both the 4" and the 6" tabbing applied, I again reviewed the application to ensure no trapped air bubbles were present.
I then turned my attention to the chainplate knees. The 3/4" plywood used for the chainplates appeared in fine enough shape, and the existing tabbing did not alarm me; however, I did want to repair a few voids and weak connection points by applying new epoxy-based 1708 biaxial cloth.
I began by wetting out all of the chainplate knees and surrounding hull surfaces with neat, or straight, epoxy resin. Back in the shop, I laid out the prepared cuts of 4" biaxial tabbing and wet those out as I had done to the bulkhead tabbing material.
I carried the 4" tabbing to the boat, and applied it to the hull on either side the chainplates.
I was not concerned with overlapping this 4" tabbing material onto the hull and chainplate knee, I simply wanted a new foundation for the 6" material to be adhered to.
I moved from the starboard side to the port side, and applied two lengths of 4" tabbing to either side of each of the chainplates.
Wit the 4" biaxial cloth applied as "foundation", I returned to the shop and proceeded to wet out the 6" biaxial material. On a cardboard pallet, I brought the 6" tabbing material to the boat and applied it to the chainplate knees.
This time, I made sure to overlap the hull and chainplate itself. Given the tabbing material is 6" in width, I made sure to evenly split the material by overlapping 3" onto the hull and 3" onto the chainplate knee.
I finished all chainplates in this manner - 4" tabbing followed by 6" tabbing. I finished each chainplate knee with a layer of 10oz cloth wrapped around the inboard edge of the chainplate itself. The two aft chainplate knees also received thickened epoxy on this inboard edge, followed by another layer of 10oz cloth. The chainplates knees, as well as the cockpit bulkhead tabbing, will get a good sanding in the coming days to ready them for paint.
Total Time Today: 4 hrs
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